The present invention relates to a cooling module having two heat exchangers, through which air flows, which are connected directly behind one another in the flow direction of the air. The heat exchangers are connected with one another at outer ends of at least one pair of their feed cases for the medium to be cooled by air, particularly the coolant radiator and the charge air cooler.
An arrangement is known from German Patent Document DE 44 25 350 A1 for connecting two or more heat exchangers to form a cooling module of the initially mentioned type. In this arrangement, plug-type pins are assigned to one of the feed cases of the heat exchangers, which normally consist of fin/tube blocks with feed cases arranged at the open ends of the tubes. The plug-type pins project transversely from the feed case and engage in corresponding brackets at the feed case of the adjacent heat exchanger. In this manner, a hinge-type folding of one of the heat exchangers onto the other is to be achieved, with the attached position being maintained by detent elements provided at the ends of the feed cases of the heat exchangers facing away from the pins.
Because of the required swivelling operation of the heat exchangers with respect to one another, such a cooling module can be mounted or demounted only if sufficient space is available. As a rule, this space is not available after the installation into a motor vehicle. In addition, if one of the two heat exchangers is provided with an additional part fitted onto the feed case, such as an expansion tank, during operation of the motor vehicle, asymmetrical acceleration and deceleration forces are exercised on the feed case. Because of the resulting bending forces, these asymmetrical acceleration and deceleration forces may cause the connection between the feed case and the tube bottom and/or the fin/tube block to be impaired or become untight. Also, in a charge air cooler, the hot and pressurized air is asymmetrically introduced into the feed case. Because of the resulting forces which act upon the feed case, deformations can also be caused. In the long run, these deformations may lead to damage to the heal, exchanger or may make it necessary to correspondingly reinforce the feed cases and, as a result, make them undesirably heavy.
It is an object of the present invention to further develop a cooling module of the initially mentioned type such that it is less susceptible to asymmetrically introduced forces.
For achieving this object, a cooling module of the initially mentioned type is provided with at least one additional fastening point between the outer ends of the feed cases. Thus, the two feed cases are connected with one another in a stable manner so that they form a unit for the absorption of forces which otherwise act only upon one of the feed cases. As a result, without taking any significant additional measures to reinforce the individual feed cases, a decisive stiffening of the then formed block of two feed cases will occur. The block is made much more stable, and the connections to the fin/tube blocks are relieved by a uniform distribution of forces to both connections.
As a further development of the invention, for a cooling module with an additional part fitted onto one of the feed cases, particularly with an expansion tank fitted onto the feed case of the coolant radiator, the feed case of the coolant radiator may be equipped with a connection piece projecting to the adjacent feed case of a charge air cooler. The connection piece, for forming another fastening point, engages form-lockingly into an opening in the feed case of the charge air cooler. As a result of this further development, the acceleration and deceleration forces occurring, during operation, on a fitted-on expansion tank can be absorbed in a simple manner by both feed cases and thus by both heat exchangers.
As yet a further development of the invention, in such an embodiment, the expansion tank and the connection piece may be shaped in one piece to the feed case of the coolant radiator, and the connection piece can be provided with a relatively large cross-section and with threaded openings on the face side. Fastening screws, which are held on the feed case of the charge air cooler, are engaged in these threaded openings. As a result of this further development, mounting or demounting of the two heat exchangers is permitted by a parallel mutual displacement for which no more space than a space which corresponds approximately to the length of the fastening connection piece is necessary. Therefore, as a rule, a cooling module of this type can also be demounted in the installed condition in the motor vehicle, if this should be required.
As yet a further development of the invention, the opening in the feed case of the charge air cooler can be arranged in a bracket-type reinforcement and may be provided with a stop edge for a disk through which the fastening screws are guided. This embodiment results in a stable but relatively easily producible fastening of the feed cases on one another.
In a still further development of the invention, mutual fastening of the feed cases on their ends can take place by a stud which form-lockingly penetrates the two feed cases at a first end of the feed cases, by a connection piece which is provided in the center area and form-lockingly engages in the opening of the adjacent feed case, and, at the other end of the feed cases, by way of a bracket projecting from a side part. This bracket is expediently mounted on the side part of the coolant radiator and is fastened to the feed case of the charge air cooler by way of a screw extending with its axis perpendicular to the axes of the connection piece and the stud. As a result of this further development, fastening of the feed cases of the coolant radiator and of the charge air cooler takes place by two fixed bearings and one movable bearing formed by the bracket, which maybe arranged on the side of the feed case for the charge air cooler assigned to the air inlet connection piece of the charge air cooler. As a result of this further development, a certain linear expansion of the feed case of the charge air cooler is not hindered on the side acted upon by the hot charge air, so that damage from linear expansions is prevented.
The invention is illustrated in the drawing figures and will be described in the following.